Question: My iris plants are rotting. Their stems have a really bad aroma. What causes that, and what can I do to stop it quickly?

Answer: That’s probably a bacterial soft rot. They’re usually soil-borne, and control is difficult. Removing the affected plants is critical. Be careful, too, not to damage the crowns of the healthy plants as you cultivate around them, and don’t handle healthy plants after you have worked with the sick ones. This disease usually indicates poor drainage and limited air circulation.